Spectrochim Acta A Mol Biomol Spectrosc. 2026 May 12;360:128062. doi: 10.1016/j.saa.2026.128062. Online ahead of print.
ABSTRACT
A novel meta-substituted azo compound, (E)-1-((3-methoxyphenyl)diazenyl)naphthalen-2-ol (m-AZO), was synthesized via diazotization-coupling reaction in 90% yield. The molecular structure was unambiguously determined by single-crystal X-ray diffraction, revealing a monoclinic crystal system (space group P21/c) with the azo group in a trans configuration. Experimental characterization was carried out using FT-IR, UV-Vis, and 1H/13C NMR spectroscopy, along with elemental (CHN) analysis. The UV-Vis spectrum showed an absorption maximum at 483 nm, consistent with π-π* electronic transitions. DFT and TD-DFT calculations reproduced the experimental absorption spectrum and provided further insights into the electronic structure. Theoretical analysis of the three positional isomers (o-, m-, and p-AZO) indicated that m-AZO possesses the lowest reorganization energy for holes (λhole = 0.13 eV), while p-AZO exhibited the highest light harvesting efficiency (LHE = 81.05%). Photovoltaic simulations based on the Scharber model predicted a power conversion efficiency of 6.5% for the m-AZO/PC71BM heterojunction. These findings demonstrate that m-AZO combines favorable experimental properties with promising optoelectronic behavior, establishing it as a strong donor candidate for organic photovoltaic applications.
PMID:42143482 | DOI:10.1016/j.saa.2026.128062
